turbo_bu
December 12th, 2012, 05:47 AM
Noticed that on the E38 and E67 ECM's there are variables that deal with variable speed fuel pumps .. PWM controlled fuel pumps it looks like. Ref: {F0580} and {F0581}. On the few vehicles that I looked at, it lists No and the PWM table is all 90% ... thus, the ECM is just commanding the fuel pump to be powered on.
The reason for asking about this "feature" is that many of the aftermarket large fuel pumps use a PWM controller so that the they don't over heat the fuel. It would be nice if the existing ECM had a way of commanding either the controller, or powering directly the fuel pumps using PWM. Didn't know if anyone had played with this, or had tried to make it work. I "think" I read that the Mustangs ECM utilizes PWM for their fuel pump control.
The reason for asking about this "feature" is that many of the aftermarket large fuel pumps use a PWM controller so that the they don't over heat the fuel. It would be nice if the existing ECM had a way of commanding either the controller, or powering directly the fuel pumps using PWM. Didn't know if anyone had played with this, or had tried to make it work. I "think" I read that the Mustangs ECM utilizes PWM for their fuel pump control.